Energy-based operation management of heating systems

01Initial situation

Around 38% of the total energy consumption in the Federal Republic of Germany relates to "building energy", and the largest part of this to heating and hot water generation. The efforts to increase efficiency when it comes to heating buildings are thus accordingly high: by using more economical boilers, thicker wall insulation, triple glazing, etc.

What has remained pretty much ignored to date is, however, the optimisation of the overall system during normal operation through continuous energy-based operation management. At the moment, focus is placed on ensuring heating systems run without any errors; ensuring energy-efficient operation is hardly looked into systematically. However, the overall heating systems of large residential buildings are so complex, that optimum energy efficiency can only be achieved through the systematic observation of all components together with their continuous monitoring and control.

02Up to fifteen percent energy savings

Heating systems are often located in basements - which means they have to put up with a life in the shadows. They are only considered under two conditions: When the house stays cold - or when the latest heating bill demands an additional payment. Which means optimum operation cannot be achieved!

The company Energiezentrale Nord GmbH, which is based in Norderstedt, has set itself the goal of ensuring the heating systems of large residential buildings no longer remain ignored. In large residential buildings (current heating costs: over 30,000 EUR/year), the gas consumption (with large multi-boiler systems, individually for each boiler) is measured continually, and for all items that use electricity, such as pumps, blowers, burners, etc., the power consumption is also determined separately. At the same time, it is also determined just how much energy is produced at all times by the heating system for heating and the generation of hot water.

03The "physical optimum"

In cooperation with the Fraunhofer Institute for Factory Operation and Automation (IFF Magdeburg), the so-called physical optimum is determined: Using the amount of heat provided, the absolute quantity of gas and electricity needed to produce this is calculated. By comparing these base values, all operating conditions can be examined in relation to their efficiency. Each deviation can then be determined, and the cause can be identified and removed by monitoring all of the equipment.

The energy savings of between ten and fifteen percent are achieved in multiple stages:

  • The commissioning of heating systems generally takes place nowadays without taking the energy optimum into consideration. Focus is placed on compliance with the specifications of the manufacturer and ensuring fault-free operation, but nothing else. Through continuous monitoring, the original settings can be optimised from an energy perspective.
  • Following this, any major deviations from the optimum energy efficiency level are viewed as a fault and dealt with immediately, long before such things are usually noticed by the property management.
  • Further energy savings are also made possible through the continuous measurement and optimum configuration of the various load conditions, such as in line with the outside temperature, the time of day or day of the week, etc.

 

04Save energy and money

Another savings effect is produced by the early identification of faults and the fast, secure diagnosis of the causes. This means faults can be rectified before they have even been noticed during operation of the system.

What’s more, faults can be dealt with more quickly and in a targeted manner: The heating system technician is aware of the fault before actually reaching the site, as he will have retrieved the measurement data in advance and will thus know which setting needs adjusting or which part needs replacing.

The project is being supported with funds from the support programme "Einsparzähler" (Energy Saving Counter) over a period of 4.5 years. During this time, 60 large residential buildings in Northern Germany will be optimised from an energy perspective. According to preliminary research, energy savings of 10 to 15% can be expected - which corresponds with the savings that are usually expected with outer wall insulation on buildings (which is associated with a great deal of outlay).

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